The son of a doctor, he enrolled at a young age in the Toledo Infantry Academy, where Francisco Franco was a fellow cadet.

He, along with Franco and General Eduardo López Ochoa, helped suppress a workers uprising in Asturias using Moroccan Regulars and Legionnaires in 1934.

He was a strong early supporter of the Falange Española and a close personal friend of José Antonio Primo de Rivera.

When Niceto Alcalá-Zamora was replaced as President of the Republic by the left-wing Manuel Azaña on 10 May 1936, a group of Spanish Army officers, including Yagüe, Emilio Mola, Franco, Gonzalo Queipo de Llano and José Sanjurjo, started plotting to overthrow the democratically elected Popular Front government.

[10][page needed] Yagüe never showed panic even when the enemy was close by, and was able to adjust battle plans quickly to suit changing circumstances.

[citation needed] After the collapse of the Second Spanish Republic in 1939, Yagüe was promoted to major-general and appointed as Minister of the Air Force by General Franco.